BIND 9.3.2 on FreeBSD 6.1 out of control
google at gushi.org
Wed Jan 17 04:30:25 UTC 2007
I'll try this once BIND 9.4 settles into ports. Jinmei, thanks for all
JINMEI Tatuya / 神明達哉 wrote:
> >>>>> On Mon, 15 Jan 2007 16:17:27 -0600,
> >>>>> "Matthew Schlosser" <mschlosser at eschelon.com> said:
> >> I've often heard this type of symptom, especially on FreeBSD. One
> >> common cause is that BIND9's cache cleaning (prior to 9.4) relies on
> >> system's malloc()/free() routines, which could run inefficiently on
> >> FreeBSD (I'm not really sure if it's still the case for 6.1, but it
> >> was at least for some 4.X versions); and one common workaround is to
> >> enable BIND9's internal memory allocator by rebuilding BIND9 with:
> >> % ./configure STD_CDEFINES='-DISC_MEM_USE_INTERNAL_MALLOC=1'
> >> This should be very effectively particularly for the case of cache
> >> cleaning because it will most likely recycle pre-allocated memory
> >> fragments without involving any system calls or possible-inefficient
> >> standard libraries.
> > Could this affect the problem I'm having (see message "Bind9 Crazy-high CPU
> > on Linux")? The symptoms are similar, but not the same.
> Perhaps, but it also depends on details of the problem and of your
> environment, especially the memory usage when the problem occurs and
> whether you specify max-cache-size (and if yes the value of the
> It should also be noted that even if the use of the internal allocator
> mitigates the problem it doesn't change the fact that cache cleaning
> is a heavy task. So, while cleaning the cache, the CPU will still be
> pretty busy (the busy period will probably be shortened), and some
> incoming queries may still be dropped during the period. BIND 9.4
> remedies the query drop issue further, by adjusting non-interruptible
> cleaning periods (during which queries aren't processed) based on
> average query rate.
> In summary,
> - the internal allocator on 9.3 may help, but the CPU will still be
> busy (though the busy period may be shorter) and queries may still
> be dropped during the busy period.
> - 9.4 may also help, and hopefully there will be no query drops;
> however, the CPU will still be busy for some shorter period.
> JINMEI, Tatuya
> Communication Platform Lab.
> Corporate R&D Center, Toshiba Corp.
> jinmei at isl.rdc.toshiba.co.jp
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